Water whistle



FIG. 1 is a side elevational view of a water whistle showing our new design, the side opposite being substantially a mirror image;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof, with the hose member removed for ease of illustration.

The unshown bottom of the claimed design is plain and unornamented. 

The ornamental design for a water whistle, as shown and described. 